LAPACK  3.10.0 LAPACK: Linear Algebra PACKage

## ◆ zswap()

 subroutine zswap ( integer N, complex*16, dimension(*) ZX, integer INCX, complex*16, dimension(*) ZY, integer INCY )

ZSWAP

Purpose:
`    ZSWAP interchanges two vectors.`
Parameters
 [in] N ``` N is INTEGER number of elements in input vector(s)``` [in,out] ZX ` ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )` [in] INCX ``` INCX is INTEGER storage spacing between elements of ZX``` [in,out] ZY ` ZY is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCY ) )` [in] INCY ``` INCY is INTEGER storage spacing between elements of ZY```
Further Details:
```     jack dongarra, 3/11/78.
modified 12/3/93, array(1) declarations changed to array(*)```

Definition at line 80 of file zswap.f.

81 *
82 * -- Reference BLAS level1 routine --
83 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
84 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
85 *
86 * .. Scalar Arguments ..
87  INTEGER INCX,INCY,N
88 * ..
89 * .. Array Arguments ..
90  COMPLEX*16 ZX(*),ZY(*)
91 * ..
92 *
93 * =====================================================================
94 *
95 * .. Local Scalars ..
96  COMPLEX*16 ZTEMP
97  INTEGER I,IX,IY
98 * ..
99  IF (n.LE.0) RETURN
100  IF (incx.EQ.1 .AND. incy.EQ.1) THEN
101 *
102 * code for both increments equal to 1
103  DO i = 1,n
104  ztemp = zx(i)
105  zx(i) = zy(i)
106  zy(i) = ztemp
107  END DO
108  ELSE
109 *
110 * code for unequal increments or equal increments not equal
111 * to 1
112 *
113  ix = 1
114  iy = 1
115  IF (incx.LT.0) ix = (-n+1)*incx + 1
116  IF (incy.LT.0) iy = (-n+1)*incy + 1
117  DO i = 1,n
118  ztemp = zx(ix)
119  zx(ix) = zy(iy)
120  zy(iy) = ztemp
121  ix = ix + incx
122  iy = iy + incy
123  END DO
124  END IF
125  RETURN
126 *
127 * End of ZSWAP
128 *